YOU SAID:

I would walk like half a mile

INTO JAPANESE

私は半マイルのように歩くだろう

BACK INTO ENGLISH

I will walk like half a mile

INTO JAPANESE

私は半マイルほど歩くだろう

BACK INTO ENGLISH

I will walk for half a mile

INTO JAPANESE

私は半マイル歩くだろう

BACK INTO ENGLISH

I will walk half a mile

INTO JAPANESE

私は半マイル歩くだろう

BACK INTO ENGLISH

I will walk half a mile